In recent years, there has been a mammoth increase in the amount of offshore oil and gas exploration, and in other uses of offshore areas. Wells have been drilled in both coastal waters and in the open seas. As the need for oil becomes ever increasing, there is likely to be a vast expansion of exploration and development activities in these offshore areas. In nearly all cases, such exploration and development requires the use of subsea structures and facilities. In relatively shallow waters (less than 200 feet), the oil wells are usually drilled from platforms that rest on the bottom; the drilling platform is constructed above the highest expected waves. In deeper waters and for exploratory work, drilling is done from a floating vessel that is kept in place by a combination of anchors and motors. The building of these offshore platforms and subsea structures requires a great amount of welding and structural integrity. In order to insure such structural integrity and weld acceptability, it is necessary to continually carry out defect and flaw inspection in these subsea structures. As it exists now, visual inspection is one of the most effective way of determining whether the welds and structures have satisfactory integrity. Other techniques are also employed to inspect these subsea surfaces. These techniques may include acoustics, x-rays, and magnetic particle inspection. Unfortunately, the ability to carry out these subsea inspections is hampered, both physically and economically, by the buildup of soft and hard marine growth and accretions.
Over time, any subsea structure will develop a large amount of such growth. These growths can include algaes, sponges, and calciferrous marine growths (e.g., barnacles, corals, and incrustations). Accretions are caused by naturally occurring electrolysis in deep sea. These can be likened to solid mineral deposits caused by electroplating. In all cases, these growths must be removed in order to carry out effective defect and flaw inspections.
In the past, this cleaning was carried out by using grit blasters and water blasters. Grit blasters are a type of underwater sand blaster. The water blasters shoot a stream of water at the marine growth buildup at between 10,000 and 30,000 p.s.i. The cost of using either of these aforestated techniques is extremely expensive. In addition to being expensive, grit blasters and water blasters many times fail to effectively remove the marine growth deposits, especially black oxides found in depths beyond the soft marine growth zone.
In addition to offshore oil wells, there are many, many other applications for underwater cleaning operations. Ships occasionally require underwater cleaning so as to improve the hydrodynamics of the vessels. Underwater pipelines require cleaning for defect and flaw inspections. Many port facilities have supports extending deeply into the water. These supports are often times are subject to visual inspection for flaws and defects.
Until the present invention, it was thought difficult and expensive to clean these underwater surfaces. In addition, the personnel and equipment were unavailable to carry out these cleaning activities at depths beyond conventional mixed gas diving. As a result, flaw and defect inspection activities were delayed or unable to be carried out effectively.
It is an object of the present invention to provide an optical cleaning system for efficiently and effectively removing marine growths from underwater surfaces.
It is another object of the present invention to provide an optical cleaning system that removes matter from underwater surfaces in a cost and time effective manner.
It is still a further object and advantage of the present invention to provide an optical cleaning system that can be remotely manipulated and utilized without divers.
It is still a further object and advantage of the present invention to provide an optical cleaning system that reduces the need for deep sea diver manpower.
These and other objects and advantages of the present invention will become apparent from a reading of the attached specification and appended claims.